As a wireless communications network develops in aspects such as topology, user capacity, access technology, and data throughput rate, how to test stability of a new cell, a base station, and even an entire coordination network in an ultimate-capacity case by using limited devices and limited antenna ports becomes a problem urgently needing to be resolved in the test field.
In actual application, a user equipment (UE for short) simulation device may be used to text stability of a network-side device (for example, a base station) in an ultimate-capacity state. The UE simulation device may generate a large quantity of UE signals by using an architecture of “digital signal processor (English: Digital Signal Processor, DSP for short)+field-programmable gate array (English: Field-Programmable Gate Array, FPGA for short)”, and output the UE signals by using a cable or an air interface. However, when the UE signals are output by using an air interface, the UE simulation device has limited antennas, and usually has a few of or tens of limited antennas, but there may be hundreds, thousands, or even ten thousands of simulated UE signals. Therefore, when the quantity of the simulated UE signals is far greater than the quantity of the antennas of the UE simulation device, some UE signals need to be combined, and the combined UE signals are sent by using one antenna. A simulated UE signal is usually a digital signal. Therefore, when a large quantity of UE signals are combined, because a high-power UE signal has a relatively large quantization error during quantization, the quantization error of the high-power UE signal inevitably covers that of a low-power UE signal, causing distortion of the low-power UE signal. Consequently, decoding on the low-power UE signal on the network-side device fails, corresponding UE cannot communicate with the network-side device, and test accuracy of stability of the network-side device in the ultimate-capacity state is affected.
Therefore, a test device and method that can output a UE signal from an air interface without distortion are needed.